As early cancer or disease detection and diagnosis make further inroads into clinical practice, the high cost of current disease screening techniques redirected the focus of the investigators towards methods capable of quantifying the risk towards these diseases as a practical pre-screening tool. One particular application area is epidemiological science and public health research into cancer prevention, so the invention is applicable for a wide variety of chronic or slowly developing diseases such as Alzheimer's, or Multiple Sclerosis. However, prevention required identification of the population at risk in association with an appropriate prevention or risk reduction intervention for example through the control of disease inducing agents or lifestyle changes (exercise, diet etc.) An example risk quantification is the work related to assessing the breast cancer risk in the general population or subgroups thereof by Boyd, Yaffe et al. (1-3) which showed that X-ray density patterns are identified as having one of the highest odds ratios towards the risk of breast cancer between the low risk and the high risk groups. For the specific case of breast cancer, radiologically dense breast tissue on mammography indicates the presence of stromal and epithelial tissue in the breast, the amount of which is strongly related to risk of breast cancer, with increasing amount of radiologically dense tissue related to increased risk. The ability to assess the breast cancer risk enables new steps in cancer prevention, for example through lifestyle and dietary changes (4).
One of the major disadvantages of the current standard for Breast Cancer Risk assessment is the use of ionizing radiation. This results in the late introduction of this diagnostic modality during the life of a woman, due to the inherent risk when using ionizing radiation in a diagnostic modality. Other good risk predictors are in general also only available once a woman has reached around 40 years of age, such as cancer incidence in first degree relatives (mother and sisters). However, the late onset in using these risk assessment modality will reduce the available time frame for any intervention aimed at reducing the disease risk. Hence, there is a clear need for a non-ionizing modality which can be employed in young patients, here in post puberty pre-menopausal women.
Non-ionizing radiation was employed in various optical mammography approaches, usually in attempts to image the breast, and to detect breast lesions (5,6) commonly using frequency domain technologies at only a few specialized wavelengths, or as spectroscopic approaches for the determining the tissue optical properties of normal versus malignant breast tissue (7). These spectroscopic applications, including an article by Egan and Dolen (8) are rather intended for determination of the probability for the presence of cancer, but do not address the concept of risk assessment, e.g. as a pre-screening tool.
U.S. Pat. No. 6,121,775 is directed to an MRI imaging method and apparatus and provides a physical interrogation methods related to detecting small changes in tissue.
U.S. Pat. No. 5,079,698 is directed to a transillumination method and apparatus for the diagnosis of breast tumors and other breast lesions by normalization of an electronic image of the breast. U.S. Pat. No. 6,002,958 is directed to a method and apparatus for diagnostics of internal organs. This patent teaches the use of NIR radiation in the 0.6-1.5 um wavelength range and adds ultrasound to the analysis tools. These two patents specifically create images of the organ
U.S. Pat. No. 6,095,982 discloses a spectroscopic method and apparatus for optically detecting abnormal mammalian epithelial tissue' covers only Raman and fluorescence methods. U.S. Pat. No. 6,069,689 discloses an apparatus and methods relating to optical systems for diagnosis of skin diseases while very generally written and addressing, reflectance, fluorescence and Raman, using a plurality of light emitting diodes. While some changes in the tissue (skin) are mentioned the idea of risk assessment is not included in this or any other patent related to the use of non-ionizing radiation.